The U.N. nuclear watchdog is due to report on Iran's nuclear program next week, amid renewed speculation about a possible Israeli or U.S. military attack on the Islamic Republic.
Israel, where much of the speculation has originated, staged a mass drill on Thursday, simulating the effect of a missile attack, a day after it test-fired a long-range missile.
Israel, the United States and European powers suspect Iran is trying to build a nuclear weapon capability. Tehran says its program is for peaceful, civilian purposes.
Here are some details on how Israel and Iran shape up militarily:
* ISRAEL ARMED FORCES
Israel has 176,500 personnel on active service made up of 133,000 in the army, which includes 107,000 conscripts. There are 9,500 in the navy and 34,000 in the air force. There is a reserve of 565,000.
MAIN BATTLE TANKS: 3,501, including 441 Merkava MkI, 455 Merkava MkII, 454 Merkava MkIII, 175 Merkava MkIV and 206 Centurions.
ARMOURED PERSONNEL CARRIERS: 10,484
ARTILLERY: 5,432 artillery pieces, including 620 self-propelled and 456 towed.
-- 3 Dolphin (GER type 212 variant) tactical submarines and 57 patrol and coastal combatants, including 3 corvettes.
-- 460 combat capable aircraft, with 168 fighters, including 27 F-15A Eagle, 7 F-15B and 90 F-16-A Fighting Falcons; 227 ground attack fighters; 65 attack aircraft.
-- 9 tanker/transport aircraft and 77 other transport aircraft.
-- 81 attack helicopters, including 30 AH-1E/AH-1F Cobra and 30 AH-64A Apache; 200 transport helicopters.
-- air defense includes 48 towed SAMs and 920 guns.
* STRATEGIC FORCES
-- Israel is widely believed to have a nuclear capability. Delivery means include Jericho 2 intermediate-range ballistic missiles and Jericho 1 short-range ballistic missiles.
-- It is believed to have up to 200 nuclear warheads.
-- Iran has more than 523,000 personnel on active service, comprising 350,000 in the army, including 220,000 conscripts. The Islamic Revolutionary Guards Corps, viewed as the most loyal guardian of the ruling system, has another 125,000.
-- 18,000 naval personnel and 30,000 air force personnel including 12,000 air defense. Reserves of 350,000.
MAIN BATTLE TANKS: 1,613, including some 100 locally produced Zulfiqar, about 100 elderly British-made Chieftain Mk3 and Mk5, and 150 U.S.-made M-60A1, as well as 480 Soviet-designed T-72, 540 T-54/T-55.
ARMOURED PERSONNEL CARRIERS: About 640.
ARTILLERY: 8,196 artillery pieces of which 2,010 towed and over 310 self-propelled.
-- 23 submarines, including 15 tactical; 3 Kilo class (RUS Type 877) attack submarines, 12 midget submarines and 8 swimmer delivery vehicles.
-- More than 100 patrol and coastal combatants, including 6 corvettes, 13 patrol craft, 4 patrol boats, 21 semi-submersible boats and 56 various other patrol vessels.
* AIR FORCE:
-- 336 combat capable aircraft.
-- 189 fighter aircraft including 20 F-5B, 60 F-5E Tiger II and 35 Mig-29A.
-- 108 ground attack aircraft.
-- 116 transport aircraft.
-- 30 Bell 214C maritime reconnaissance helicopters.
-- Air defense has more than 279 SAM missiles.
-- Iran's strategic missiles are controlled by the Revolutionary Guards.
-- It has around 300 short-range ballistic missiles, including Shahab-1 (Scud-B), Shahab-2 (Scud-C), as well as Tondar-69 (CSS-8).
-- It has Shahab-3 strategic intermediate range ballistic missile (IRBM) with a range of up to 1,000 km, the Ghadr-1 with an estimated 1,600 km range and a Shahab-3 variant known as Sajjil-2 with a range of up to 2,400 km.
-- In January 2009, Iran said it had tested a new air-to-air missile. On March 7, 2010, Iran said it had started producing short-range cruise missiles which it described as highly accurate and able to destroy heavy targets.
-- The Revolutionary Guards have 24 launchers of which 12 to 18 are for the short range Shahab 1-2, and at least 6 for the Shahab-3, Ghadr-1 and Sajjil-2.
Sources: Reuters/2011 Military Balance/CSIS Report on Gulf Miltary Balance 2011 (Reporting by David Cutler, London Editorial Reference Unit)